1. Field of the Invention
The present invention relates to a magnetic recording medium, a manufacturing method thereof, and a magnetic recording/reproducing apparatus, and more particularly, to a magnetic recording medium having a rewritable RAM (Random Access Memory) region and an unrewritable ROM (Read Only Memory) region, a manufacturing method of the magnetic recording medium, and a magnetic recording/reproducing apparatus including the magnetic recording medium.
2. Description of the Related Art
In response to demand for an increase in storage capacity, a recent magnetic recording device, a magnetic disk drive, and a hard disk drive must increase recording density of a magnetic recording medium. However, in association with an increase in recording density, there is arising a problem that magnetic information recorded by a read/write head, which moves over the medium relatively, affects recording of an adjacent track. There has been proposed a countermeasure for avoiding such a problem by physically separating magnetic substances in adjacent tracks (see, e.g., JP-A-Sho. 62-256225).
Magnetic substances on a magnetic recording medium are patterned to record t servo information and ROM information according to presence or absence of the magnetic substances (see, e.g., JP-A-Hei. 10-255407).
The method for patterning a magnetic substance on a magnetic recording medium includes, for example, a nanoimprint method. This method first draws and develops a desired pattern of magnetic substances as an irregularity pattern on a master disk by using a rotary disk writing system. Next, this method forms an imprint stamper onto which the irregularity pattern on the surface of the master disk are transferred, from the master disk. Then, the method presses the imprint stamper against a resist film applied over the recording medium, thereby transferring the irregularities on the surface of the stamper to the resist film. Finally, the method transfers the irregularities on the surface of the resist film to a lower recording layer by means of a technique, such as etching, to thus pattern the magnetic substances.